<template>
    <div>
        <div class="item1">
            <div class="item"></div>
        </div>
        <div class="item2">
            <div class="item"></div>
        </div>
        <div class="item3">
            <div class="item"></div>
        </div>
    </div>
</template>
<style scoped>
.item{
    background: red;
    height: 100px;
    width: 100px;
    border: 1px solid #000;
}
.item1{
    display: flex;
    flex-direction: column;
    align-items: center;
    /* justify-content: center; */
    height: 120px;
    }
.item2{
    display: flex;
    justify-content: flex-start;
    }
.item3{
    display: flex;
    justify-content: flex-end;
    }
</style>